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Lungs of isopods, a taxon of crustaceans that include woodlice and pill bugs. From dry to humid environments the size of the lungs and the type of embedding into the body is reduced. After Hoese (328).
Source publication
Life originated in anoxia, but many organisms came to depend upon oxygen for survival, independently evolving diverse respiratory systems for acquiring oxygen from the environment. Ambient oxygen tension (PO2 ) fluctuated through the ages in correlation with biodiversity and body size, enabling organisms to migrate from water to land and air and so...
Contexts in source publication
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... example, prim- itive Oniscoidea and its subordinate taxon Crinocheta, gas exchange takes place at the thin-walled ventral surface of the exopodites of pleopods. More complex lungs are covered or completely internalized with a larger surface area composed of tubules and wrinkles. These lungs are highly specialized for extreme arid habitats (592) (Fig. 7). One example is the genus Periscyphis (Oniscidea, Eubelidae). The lungs begin at occludable spiracles on the posterior pleopodal exopodite, enter into a sacciform atrium and end in an enormous number of tubular, trachea-like structures that fill a large proportion of the abdominal segment (pleon) (221). Respiratory water loss is ...
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... arches (295). Although fine structure of the gas-exchange units in all "fishes" from hagfish to tuna is fundamentally similar and all vertebrate gills lie in the posterior pharynx, everything in between changes as one ascends the phylogenetic tree. In con- trast to Chondrichthyes, a separate cartilaginous ray supports each filament in bony fishes (Fig. 17). In basal Actinopterygii, for example, reed fish (Cladistia) and sturgeons (Chondrostei), the holobranchial septa are nearly complete as in chimaeras, and only the free tips of the filaments are supported by the rays alone. Within Teleostei, the septa become progressively reduced and in percomorphs the filaments are completely free ...
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... free except for their most proximal parts. The one-to-one relation- ship of rays to filaments may be an exaptation that allowed the evolution of free filaments. This new gill structure impacts the fine adjustment of ventilation (below). Where the filaments are not attached to the septa, respi- ratory water can flow freely between lamellae (Fig. 17). The degree to which this so-called branchial curtain allows water to escape over the ends of filaments from opposite sides of a respiratory unit depends on the activity of filamentar adduc- tor muscles (174), which have evolved separately in different teleost groups (611). In addition, the degree to which the base of the lamellae are ...
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... for example, primitive Oniscoidea and its subordinate taxon Crinocheta, gas exchange takes place at the thin-walled ventral surface of the exopodites of pleopods. More complex lungs are covered or completely internalized with a larger surface area composed of tubules and wrinkles. These lungs are highly specialized for extreme arid habitats (592) (Fig. 7). One example is the genus Periscyphis (Oniscidea, Eubelidae). The lungs begin at occludable spiracles on the posterior pleopodal exopodite, enter into a sacciform atrium and end in an enormous number of tubular, trachea-like structures that fill a large proportion of the abdominal segment (pleon) (221). Respiratory water loss is ...
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... arches (295). Although fine structure of the gas-exchange units in all "fishes" from hagfish to tuna is fundamentally similar and all vertebrate gills lie in the posterior pharynx, everything in between changes as one ascends the phylogenetic tree. In contrast to Chondrichthyes, a separate cartilaginous ray supports each filament in bony fishes (Fig. 17). In basal Actinopterygii, for example, reed fish (Cladistia) and sturgeons (Chondrostei), the holobranchial septa are nearly complete as in chimaeras, and only the free tips of the filaments are supported by the rays alone. Within Teleostei, the septa become progressively reduced and in percomorphs the filaments are completely free ...
Context 6
... completely free except for their most proximal parts. The one-to-one relationship of rays to filaments may be an exaptation that allowed the evolution of free filaments. This new gill structure impacts the fine adjustment of ventilation (below). Where the filaments are not attached to the septa, respiratory water can flow freely between lamellae (Fig. 17). The degree to which this so-called branchial curtain allows water to escape over the ends of filaments from opposite sides of a respiratory unit depends on the activity of filamentar adductor muscles (174), which have evolved separately in different teleost groups (611). In addition, the degree to which the base of the lamellae are ...
Citations
... Moreover, intentional breathing, as highlighted by Zaccaro et al. (2018), optimizes oxygenation throughout the body, supporting optimal cellular function. The interconnectedness of the respiratory and immune systems becomes evident, with intentional breathing aiding in efficiently eliminating toxins and waste products, thereby supporting the body's natural detoxification processes (Hsia et al., 2013). ...
... The observed improvements in physical condition, nasal and throat conditions, and sensibility status underscore the potential of intentional breath regulation in alleviating hay fever symptoms. These positive outcomes align with the broader literature on the benefits of intentional breathing on respiratory and immune system functions (Zaccaro et al., 2018;Hsia et al., 2013). The significant reduction in symptoms such as head/sinus/tooth tenderness, face/sinus/tooth pressure, ear pain, blockage, fullness or stuffiness after the Nadi Shodhan Yoga intervention suggests a tangible impact on the physical manifestations of hay fever. ...
Hay fever, or allergic rhinitis, poses significant challenges globally, impactingindividuals with symptoms like sinus issues, sneezing, and nasal congestion.Traditional medical approaches often focus on symptom relief, promptingexploration into holistic alternatives such as Nadi Sodhan (alternate nostrilbreathing). Grounded in ancient yogic practices, Nadi Sodhan involves rhythmicbreathing to harmonize life-force energy. Recognizing a lack of dedicated studiesin this area, our research aimed to investigate Nadi Sodhan Yoga’s potentialimpact on sinus symptoms associated with hay fever. Involving 22 participants,randomly assigned to Nadi Sodhan Yoga or control groups, the study spannedan eight-week intervention using the Rhinoconjunctivitis Quality of LifeQuestionnaire to assess sinus symptoms. Results revealed a significant reductionin troublesome symptoms, indicating the potential of Nadi Sodhan Yoga inmanaging hay fever-related sinus issues. The study emphasizes the holisticbenefits of intentional breath regulation, offering insights into innovativeinterventions for allergic rhinitis. Further exploration could deepen ourunderstanding of the intricate link between intentional breath regulation andrespiratory health, fostering holistic approaches to related conditions.
... The water-to-land transition is a milestone in the evolution history of vertebrates. The emergence of air-breathing organs corresponds with the shift in oxygen medium from water to air and facilitates vertebrate terrestrialization 1,2 . In tetrapods, lungs serve as air-breathing organs, and their functionalization is a tightly regulated multistage process that involves ventilation, oxygenation, and a response to exogenous stimuli [3][4][5] . ...
The evolution and development of vertebrate lungs have been widely studied due to their significance in terrestrial adaptation. Amphibians possess the most primitive lungs among tetrapods, underscoring their evolutionary importance in bridging the transition from aquatic to terrestrial life. However, the intricate process of cell differentiation during amphibian lung development remains poorly understood. Using single-cell RNA sequencing, we identify 13 cell types in the developing lungs of a land-dwelling frog (Microhyla fissipes). We elucidate the differentiation trajectories and mechanisms of mesenchymal cells, identifying five cell fates and their respective driver genes. Using temporal dynamics analyses, we reveal the gene expression switches of epithelial cells, which facilitate air breathing during metamorphosis. Furthermore, by integrating the published data from another amphibian and two terrestrial mammals, we illuminate both conserved and divergent cellular repertoires during the evolution of tetrapod lungs. These findings uncover the frog lung cell differentiation trajectories and functionalization for breathing in air and provide valuable insights into the cell-type evolution of vertebrate lungs.
... A p rinci p a l tenet of conservation p hysio logy i s th at organisms' p hysio log ica l syst ems are adapt ed t o enable h om eosta si s in their native hab i ta t, poten t ia l ly leaving th em vuln era ble to anthropog enic chan g es to natural l andsc apes ( Bennett and Huey 1990 ;Feder et al. 2000 ;Cooke et al. 2014 ). Ther e ar e few (if any) more importan t in tegra ted p hysio logical syst ems t o the continue d surviva l and s ucces s of anim al s th an th e de livery of oxygen from t he exter nal environment to internal tis s ues and or gan s. Thi s ch a l len g e is most p ro n oun ced during hypoxia (low levels of disso l v ed oxyg en) when oxygen is scarce an d con cen tra tion gradien ts are unfav ora ble for oxygen acquisition ( Bickler and Buck 2007 ;Mandic et al. 2009 ;Hsia et al. 2013 ). Hypoxia is espe-cia l ly a concern for aquatic anim al s, for which oxygen mu st be di sso l ved in water as o p p osed to b eing consistentl y availab le in th e atm osph ere ( Schmidt-Nie lsen 1997 ). ...
Synopsis
A critical component of animal conservation in a changing world is an understanding of the physiological resilience of animals to different conditions. In many aquatic animals, hypoxia (low environmental oxygen levels) is a regular occurrence, but the likelihood and severity of hypoxia vary across habitats. Fast-flowing, stream-like habitats are never hypoxic, so long as flow is maintained. Do animals from such habitats retain the capacity to survive hypoxic conditions? We use aquatic frog tadpoles to test the effects of natural habitat on performance in hypoxia in an experimental framework, finding that stream-living tadpoles have reduced performance in hypoxia. Tadpoles also vary in lung presence, with some species able to breathe air during hypoxia. We found that among lunged tadpoles, air-breathing rates increase in hypoxia in pond-living species but not stream-living species. Lung presence was also found to influence hypoxia performance, as lungless, stream-living tadpoles were found to be especially vulnerable to hypoxia, while pond-living, lungless tadpoles appeared largely resilient to hypoxia. We consider the ramifications of our findings on conservation outlooks and strategies for frogs and their tadpoles, suggesting that stream-living tadpoles, and especially lungless, stream-living tadpoles, may be particularly at risk to factors that reduce stream flow. Thus, a primary goal for conservation and management of species with stream-living tadpoles should be the maintenance of year-round streamflow, which oxygenates waters and prevents hypoxia.
... For convection, a muscular pharyngeal pump ventilates the gills with sufficient amounts of water to meet the gas exchange requirements imposed by different metabolic and environmental challenges. Different types of muscular pumps exist across fishes (see Milsom et al. 2022;Hsia et al. 2013), but most rely on muscular contraction of the pharynx and, in many cases, elastic recoil of the bony or cartilaginous arches to move water into the pharyngeal cavity and out across the gills. Ventilation is matched by gill perfusion with a muscular heart that pumps blood through the vessels of the arches, filaments and lamellae. ...
Gill function in gas exchange and ion regulation has played key roles in the evolution of fishes. In this review, we summarize data from the fields of palaeontology, developmental biology and comparative physiology for when and how the gills first acquired these functions. Data from across disciplines strongly supports a stem vertebrate origin for gas exchange structures and function at the gills with the emergence of larger, more active fishes. However, the recent discovery of putative ionocytes in extant cephalochordates and hemichordates suggests that ion regulation at gills might have originated much earlier than gas exchange, perhaps in the ciliated pharyngeal arches in the last common ancestor of deuterostomes. We hypothesize that the ancestral form of ion regulation served a filter-feeding function in the ciliated pharyngeal arches, and was later coopted in vertebrates to regulate extracellular ion and acid–base balance. We propose that future research should explore ionocyte homology and function across extant deuterostomes to test this hypothesis and others in order to determine the ancestral origins of ion regulation in fish gills.
... Terrestrial species are known to have acquired several novel traits that are not found in ancestral aquatic species, such as hard skeletal systems that resist gravity, protective shells or skins that protect against dryness and ultraviolet light, and reproductive systems that do not require water [1,2]. One of the most important changes is in the respiratory system [3]. Major animal phyla colonizing land, such as vertebrates, arthropods and molluscs, independently acquired air-breathing organs [3][4][5][6][7]. ...
... One of the most important changes is in the respiratory system [3]. Major animal phyla colonizing land, such as vertebrates, arthropods and molluscs, independently acquired air-breathing organs [3][4][5][6][7]. However, in many cases, the detailed evolutionary processes of these traits remain unclear because of the extinction of species that had the ancestral or transitional traits [8][9][10]. ...
Background
The acquisition of air-breathing organs is one of the key innovations for terrestrialization in animals. Terrestrial isopods, a crustacean lineage, can be suitable models to study the evolution of respiratory organs, as they exhibit varieties of air-breathing structures according to their habitats. However, the evolutionary processes and origins of these structures are unclear, due to the lack of information about their developmental processes. To understand the developmental mechanisms, we compared the developmental processes forming different respiratory structures in three isopod species, i.e., 'uncovered lungs' in Nagurus okinawaensis (Trachelipodidae), 'dorsal respiratory fields' in Alloniscus balssi (Alloniscidae), and pleopods without respiratory structures in Armadilloniscus cf. ellipticus (Detonidae).
Results
In N. okinawaensis with uncovered lungs, epithelium and cuticle around the proximal hemolymph sinus developed into respiratory structures at post-manca juvenile stages. On the other hand, in Al. balssi with dorsal respiratory fields, the region for the future respiratory structure was already present at manca 1 stage, immediately after hatching, where the lateral protrusion of ventral epithelium occurred, forming the respiratory structure. Furthermore, on pleopods in Ar. cf. ellipticus, only thickened dorsal cuticle and the proximal hemolymph sinus developed during postembryonic development without special morphogenesis.
Conclusions
This study shows that the respiratory structures in terrestrial isopods develop primarily by postembryonic epithelial modifications, but the timing and mode of development vary among species with different respiratory structures. The positions developing into respiratory structures differ between uncovered lungs and dorsal respiratory fields, suggesting that these organs derive from different origins despite the similar location of their functional organs. Overall, this study provides fundamental information for evolutionary developmental studies of isopod respiratory organs.
... Studies in mammalian models have suggested that CYP2B enzymes are significantly expressed in the lungs (Chirulli et al., 2005;Lee and Dinsdale, 1995). This could explain the observation for elevated CYP2B-like activity in the rainbow trout gills, given the physiology and close functionality of both organs and the shared evolutionary trajectory of both organs as oxygen transport systems, driven by the need to maintain oxygen homeostasis in aquatic and terrestrial environments (Hsia et al., 2013). However, further evaluations would be necessary to determine why brown trout did not display a similar trend, and experimentation considering interspecific traits at the genetic level and the presence of CYP2B-regulating pathways in brown trout organs would be necessary to explain the low CYP2B-like activity displayed by the gills. ...
... [8] The most accepted theory of pathogenesis of middle ear haemorrhage is that the increased pressure transmitted to the body by the surrounding water, which tends to be evenly distributed, compresses air in closed cavities more easily than in body tissues. [9] The soft tissue lining these spaces expands because it may absorb fluid form the other parts of the human body. Filling of blood vessels in this tissue is followed by bleeding into the ventricles. ...
Middle ear hemorrhage and drowning are two topics that are often associated with violent asphyxial deaths. Understanding the relationship between these two can provide valuable insights into forensic investigations and medical examinations. When an individual drowns, the process involves the inhalation of water or other fluids, leading to a lack of oxygen supply and subsequent asphyxiation. During this traumatic event, the body undergoes significant physiological changes, including increased pressure on various organs and tissues. One specific consequence of drowning is middle ear hemorrhage. The middle ear is a delicate structure located behind the eardrum, responsible for transmitting sound signals to the brain. When subjected to intense pressure changes during drowning, such as rapid submersion or resurfacing, blood vessels in the middle ear can rupture, resulting in hemorrhage. Middle ear hemorrhage serves as an important indicator in forensic autopsies when investigating cases of violent asphyxial death due to drowning. It can help determine whether drowning was indeed the cause of death or if other factors played a role. Furthermore, studying middle ear hemorrhage in relation to drowning can aid in distinguishing between fresh and postmortem injuries. This differentiation is crucial for accurate evaluating the exact cause and manner of a fatality after forensic examinations. In conclusion, understanding the connection between middle ear hemorrhage and drowning provides valuable insights into violent asphyxial deaths. By examining this specific injury pattern during autopsies and forensic investigations, experts can unravel critical information that aids in determining cause of death accurately.
... From a physiological perspective, respiration involves the intricate procedure of drawing oxygen from the surrounding environment into cells within the human body while simultaneously expelling carbon dioxide in the opposite direction. The lungs, serving as the primary organs for respiration, consist of fibrous structures that, by themselves, cannot intake oxygen or expel carbon dioxide (Hsia et al., 2013). Instead, the task of drawing air into the lungs for oxygen and facilitating the removal of carbon dioxide is carried out by the muscles surrounding the rib cage and the diaphragm (Bott et al., 2009). ...
This research aimed to explore the impact of plank exercise training (PET) on respiratory function, body composition, abdominis performance, and autonomic nervous system (ANS). Sixty‐one young adults participated and were divided into a control group (CG, n = 31) and an exercise group (EG, n = 30), wherein PET was administered 3 days per week for 12 weeks. After the experiment, the body composition of the CG deteriorated, whereas that of the EG improved (p < 0.001). The EG exhibited a reduction of ∼34% in the mean maximum displacement and a rise of ∼20% in the mean contraction time of the abdominis. The sit‐up in the EG demonstrated a significant increase of ∼55%. In the EG, there was a substantial increase in peak expiratory force by ∼24% and forced expiratory volume in 1 s by ∼14%, accompanied by a reduction in resting respiratory rate by ∼ −9%. When compared to the CG, these alterations were significant between the two groups (p = 0.001). In the EG, there was a significant decrease in resting heart rate by ∼2%, accompanied by a decrease in sympathetic nervous activity by ∼ −5% and by an increase in parasympathetic nervous activity by ∼5%. When compared to the CG, these alterations were significant between the two groups (p = 0.001). The findings of this study revealed that implementing PET in young adults, while controlling for dietary intake and physical activity, resulted in noteworthy changes in respiratory capacity. These changes were coupled with improvements in body composition, abdominal functions, and the ANS.
... Thus, tidal ventilation of a gas-exchange organ is less effective in O 2 extraction than other ventilatory schemes that maximize partial pressure gradients and eliminate dead space. For air-breathing animals, these limitations are largely offset by the low work of ventilation associated with the low viscosity and density of air [6][7][8][9] while air's high O 2 concentration means that under most conditions they extract sufficient O 2 from the inhaled air to satisfy their metabolic demands without causing a substantial decrease in alveolar partial pressure of oxygen ( pO 2 ) [3,10]. ...
Dragonfly nymphs breathe water using tidal ventilation, a highly unusual strategy in water-breathing animals owing to the high viscosity, density and low oxygen (O2) concentration of water. This study examines how well these insects extract O2 from the surrounding water during progressive hypoxia. Nymphs were attached to a custom-designed respiro-spirometer to simultaneously measure tidal volume, ventilation frequency and metabolic rate. Oxygen extraction efficiencies (OEE) were calculated across four partial pressure of oxygen (pO2) treatments, from normoxia to severe hypoxia. While there was no significant change in tidal volume, ventilation frequency increased significantly from 9.4 ± 1.2 breaths per minute (BPM) at 21.3 kPa to 35.6 ± 2.9 BPM at 5.3 kPa. Metabolic rate increased significantly from 1.4 ± 0.3 µl O2 min⁻¹ at 21.3 kPa to 2.1 ± 0.4 µl O2 min⁻¹ at 16.0 kPa, but then returned to normoxic levels as O2 levels declined further. OEE of nymphs was 40.1 ± 6.1% at 21.3 kPa, and did not change significantly during hypoxia. Comparison to literature shows that nymphs maintain their OEE during hypoxia unlike other aquatic tidal-breathers and some unidirectional breathers. This result, and numerical models simulating experimental conditions, indicate that nymphs maintain these extraction efficiencies by increasing gill conductance and/or lowering internal pO2 to maintain a sufficient diffusion gradient across their respiratory surface.
... Seasonal long-distance migration occurs in all classes of vertebrates [1]. The phenomenon of migration, however, has reached its greatest complexity in birds, which are preadapted to migrate due to their capacity for active flight, size, and extraordinarily efficient circulatory and respiratory systems [2]. Endogenous control mechanisms are thought to regulate seasonally appropriate migratory restlessness and orientation [3] and the onset and end of migratory activity, which may have influences through seasonal changes in dietary and habitat preferences [4] such as the circannual pattern of body mass change, including fat deposition [5,6]. ...
In this study, we aimed to evaluate the development of the fattening condition and the reproductive status of the song thrush from December to February. For this purpose, the chemical and fatty acid compositions of the pectoral muscle were analyzed in relation to the fattening state of the birds. Moreover, their reproductive activity was evaluated via the anatomical and pathological examination of tissues and through the assessment of sex steroid profiles. One hundred ninety-five thrushes captured by local hunters during the 2018–2019 and 2019–2020 hunting seasons in different provinces of the Apulia region in Italy were used. The first step was the measurement of bird body mass, and the amount of subcutaneous body fat was estimated visually. During post-mortem examinations, the pectoral muscle was excised and used for chemical and fatty acid analysis and a hormone assay, respectively. Moreover, ovaries and testicles were evaluated to determine the degree of maturation and thus the reproductive status of the birds. The results regarding fattening status and fatty acid profile confirmed that in January–February, thrushes change their diet, increasing their intake of oleic acid, likely to better cope with low temperatures and prepare for long-distance migration. In both male and female thrushes, the concentrations of sex hormones confirmed a phase of reproductive quiescence from December to February, which was also confirmed through histological examination of the gonads.
